A peacock displays its tail inside its enclosure at the Tbilisi Zoo in Tbilisi, Georgia, 22 May 2017. (Photo by Zurab Kurtsikidze/EPA)

A deer runs in a rapeseed colza field near the village of Botskovichi, 160 kilometers (100 miles) west of the Belarus capital Minsk, Sunday, May 21, 2017, as warm spring weather is established across Belarus. (Photo by Sergei Grits/AP Photo)

A domestic elephant stands by a 10-year-old wild tusker with a rear leg injury in a marshy area where it is stuck at Amchang Wildlife Sanctuary, 40 kilometers (25 miles)east of Gauhati, India, Wednesday, May 24, 2017. Veterinarians are nursing the 10-year-old male elephant to help it get out of the marshy area where it was spotted stuck by local villagers five days ago. This is becoming a common occurrence in the state which has a large population of wild elephants, straying out of their herds and entering swampy areas and villages. (Photo by Anupam Nath/AP Photo)

A disabled turtle swims in a tank at a turtles hatchery in Galle, Sri Lanka May 21, 2017. (Photo by Dinuka Liyanawatte/Reuters)

A dyeing poison frog sits on an emerald tree boa in its enclosure at the Singapore Zoo's new Reptopia exhibit during a media preview on May 24, 2017. Singapore zoo will launch its new Reptopia exhibit this June school holiday. (Photo by Roslan Rahman/AFP Photo)

Twin panda cubs, born on April 24 in captivity, are pictured in an incubator at Chengdu Research Base of Giant Panda Breeding in Sichuan province, China May 23, 2017. (Photo by Reuters/China Daily)

An orangutan holds food wrapped in the shape of a “zongzi”, or rice dumpling, offered by a zookeeper ahead of the Dragon Boat festival, at a zoo in Shenzhen, Guangdong province, China May 25, 2017. (Photo by Reuters/Stringer)

A giant panda reaches for food wrapped in the shape of a “zongzi”, or rice dumpling, offered by a zookeeper ahead of the Dragon Boat festival, at a zoo in Shenzhen, Guangdong province, China May 25, 2017. (Photo by Reuters/Stringer)

A giant panda holds food wrapped in the shape of a “zongzi”, or rice dumpling, offered by a zookeeper ahead of the Dragon Boat festival, at a zoo in Shenzhen, Guangdong province, China May 25, 2017. (Photo by Reuters/Stringer)

A giant panda eats food wrapped in the shape of a “zongzi”, or rice dumpling, offered by a zookeeper ahead of the Dragon Boat festival, at a zoo in Kunming, Yunnan province, China May 25, 2017. (Photo by Reuters/Stringer)

Raccoons reach for food wrapped in the shape of a “zongzi”, or rice dumpling, offered by a zookeeper ahead of the Dragon Boat festival, at a zoo in Kunming, Yunnan province, China May 25, 2017. (Photo by Reuters/Stringer)

A woman dressed in a traditional Ukrainian embroidered shirt holds her cat as she take part in an embroidered shirt parade in central Kiev, Ukraine, May 27, 2017. (Photo by Gleb Garanich/Reuters)

A newborn Patas monkey is pictured in an incubator at a zoo in Zhengzhou, Henan province, China May 23, 2017. (Photo by Reuters/Stringer)

Newborn Patas monkeys are pictured at a zoo in Zhengzhou, Henan province, China May 23, 2017. (Photo by Reuters/Stringer)

Egyptian geese meet in the air in a park in Frankfurt, Germany, Friday, May 26, 2017. (Photo by Michael Probst/AP Photo)